Weil-McLain GV90+3
The GV90+3 is the smallest Series 2 GV90+: 70 MBH input, 65 MBH DOE heating capacity and a 91.9% AFUE rating — the highest in the line — from the cast iron boiler with stainless steel secondary heat exchanger.
Key figures
- Max input
- 70 MBH
- Max CSA output
- 65 MBH
- AFUE
- 91.9 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Weil-McLain GV90+3 in practice
The GV90+3 fires at 70 MBH CSA input for 65 MBH of DOE heating capacity and is the efficiency leader of the GV90+ range at 91.9% AFUE. It is the entry size of the high-efficiency cast iron boiler — 3.8 gallons of water content, a 30-3/4" cabinet length and a 313 lb shipping weight.
All GV90+ sizes vent in 3" pipe to 100 ft as Category IV direct-vent or direct-exhaust appliances, with 1" NPT supply and return connections and a 1/2" NPT gas connection. Series 2 adds the built-in low water cut-off, and the IBC control reports status through indicator lights and POWER-LED flash codes rather than a display.
Best suited to
- Smaller homes and high-temperature emitter systems (baseboard, radiators)
- Buyers who want the top AFUE figure in the GV90+ range
- Projects where wide cast iron waterways suit an older system's debris
Applicability and support
- Model number
- GV90+3
- Canadian availability
- available
- Production status
- current
- ROMA supplies
- Confirmed at consultation
- ROMA services
- Confirmed at consultation
- Warranty
- Series terms
Where ROMA provides on-site service
On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.
Specifications
Published specifications
Values as published by Weil-McLain. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input, maximum | 70 MBH | CSA input (maximum). |
| Output | ||
| DOE heating capacity | 65 MBH | DOE heating capacity at maximum input; the manuals also call this CSA Output. |
| Net AHRI water rating | 57 MBH | 56 MBH per the brochure and US product table; 57 MBH per the boiler manual ratings figure. |
| Efficiency | ||
| Efficiency (AFUE) | 91.9 % | 91.9% AFUE — the highest rating in the GV90+ line. |
| Domestic hot water | ||
| Domestic hot water | Heating-only boiler; domestic hot water via an indirect tank or separate appliance | |
| Venting and air | ||
| Venting | 3" PVC, CPVC, polypropylene or stainless steel (Category IV); 3" pipe on all GV90+ sizes | Canada: install per CAN/CSA B149.1 or B149.2 with a ULC S636-compliant vent kit. |
| Max. equivalent vent/air length | 100 ft (vent and air each) | |
| Physical and connections | ||
| Weight | 313 lb | Approx. shipping weight per the boiler manual and brochure. |
| Cabinet length | 30-3/4" | |
| Gas connection | 1/2" NPT | |
| Heating water connections | 1" NPT supply (male) and 1" NPT return (female) | Minimum recommended pipe 1". |
| Operating limits and other | ||
| Boiler water content | 3.8 gal | |
| Fuel | Natural gas or propane | Propane requires a conversion kit per the CA product page. |
Manuals
- GV90+ Series 2 Boiler Manual, 550-143-010/0324550-143-010/0324 · 2024-03
Alerts documented for this model
- POWER LED flashes once per second
- POWER LED 2 flashes
- POWER LED 3 flashes
- POWER LED 4 flashes
- POWER LED 5 flashes
- POWER LED 6 flashes
- POWER light flashing alone
- POWER and TSTAT/CIRC lights flashing
- POWER and PRESS SWITCH lights flashing
- POWER and FLAME lights flashing
- FLAME lights flashing
- Solid LWCO light
- LWCO light flashing alone
- TSTAT/CIRC light flashing alone
- LIMIT light flashing alone
- POWER and LIMIT lights flashing
Frequently asked questions
How big is the GV90+3?
70 MBH input at 91.9% AFUE, with 3.8 gallons of boiler water and a 30-3/4" cabinet length; it ships at 313 lb.
Does the GV90+3 have a built-in low water cut-off?
Yes — Series 2 units include an integrated low water cut-off with test button, per the boiler manual and brochure.
What net rating does the GV90+3 carry?
The boiler manual's ratings figure prints 57 MBH net AHRI, while the brochure and US product table print 56 MBH.
Questions about the Weil-McLain GV90+3?
Describe what the boiler is doing and get a straight answer about the next step.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
- Weil-McLain Canada — GV90+ · accessed September 7, 2026
- GV90+ Series 2 Boiler Manual 550-143-010/0324 · 550-143-010/0324 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.